Draft gear



June S 1946. J. R. cARDwELL DRAFT GEARS Filed Mallen 1e, 194s 2 sheets-sheet 1 INVENTOR. Y/mes [du/ell AT'TS' June 1s, 1946.. J, R, CARDWELL 42,402,1146

DRAFT GEARS 2 sheets-sheet 2 Filed March 1e, 1945 INVENTOR. ./'dmes (rdwell ATTTS ...HIIIVI llll IIW Patented `[une 18, 1946 UNITED STATES PATENT OFFICE DRAFT GEARA James R. Cardwell, Barrington, Ill.

Application March 16, 1943, Serial No, 479,359

16 Claims. 1

This invention relates -to draft gears for vehicles, and more particularly for railway cars.

One of the objects of the invention is the provision of a new and improved resilient draft gear providedy with friction means for increasing the capacity of the gear.

Another object of the invention is the provision of a new and improved draft gear of the wedge friction type having novel means for preventing splitting or bursting of the chambered follower during the final compressive movement of the gear, or when the gear goes solid.

Another object of the invention is the provision of a new and improved gear that is simple in construction, composed of few moving parts, easily assembled, and that is inexpensive to manufacture.

Other and further objects and advantages of the invention will appear from the following description, taken in connection with the accompanying drawings, in which Fig. 1 is a longitudinal section of a portion of a, railway car showing the draft gear in position thereon;

Fig. 2 is an end elevation of the gear;

Fig. 3 is a section on the line 3-3 of Fig. 1;

Fig. 4 is a section on the line fle-.4 of Fig. l;

Fig. 5 is a view similar to Fig. l, but showing a modified form of construction;

Fig. 6 is an end elevation of the gear shown` in Fig. 5;

Fig. 7 is a section on the line 'I-'I of Fig. 5;

Fig. 8 is a section on the line 8--8 of Fig. 5; and

Fig. 9 is a section on the line 9 9 of Fig. 5.

Under war conditions, which now obtain in almost all countries of the world, the demand for ferrous material in all phases of War equipment is such as to necessitate the elimination of unnecessary metal in all manufactured articles, and the reduction in weight of all equipment to a minimum. But the reduction in the amount of metal ordinarily used in draft gear housings reduces the strength of those housings to such an extent that splitting or breaking of the housing is likely to occur on compression unless provision is made for preventing it, especially in the type of gear employing friction wedge means for increase ing the capacity of the gear.

The present invention seeks to meet these requirements and remedy this diiiculty by providing a draft gear of minimum .weight which is reinforced by a collar or flange around the open end of the gear housing, and also by providing means for wedging the ,Open end 0f the. housing radially inwardly during the final compressive movement of the gear.

Referring now to the drawings, the reference character Il) designates, generally, a portion of a railway car having an end sill II and a pair of center sills I2y I3. The center sills are preferably, though not necessarily, of channel form, arranged back to back, and are spaced apart. An upper plate Il I extends across above the center and side sills, and is rigidly connected to the flanges I5, I6, of the ,center sills, as shown in Fig. 4. The front end of this plate extends over and engages `the upper ange of the end sill I I, to which it is rigidly connected. A lower plate Idil extends across beneath said center sills, and is rigidly connected to the anges thereof, as by means of rivets. This plate is directly beneath the plate I4, and has its forward end extended beneath the lower vflange of the end sill I I and rigidly secured thereto. ',Ihe ends of the center sills extend forwardly to the end sill and arev rigidly connected to the web thereof in any suitable manner, as by means ofthe angle bars Il, I8 (see Fig. il).

The end sill II is provided with an angular opening I9 through its web portion, through which an enlarged portion 2| of a drawb-ar 22 is adapted to extend, as will presently appear. The enlarged portion 2I is angular in cross-section to correspond with the opening I9 for preventing rotation of said bar, and, in the form shown, it is rectangular in cross-section. Rigidly mounted on the face of the end sill II is a reinforcing plate 23, having a rectangular opening therein which registers with the opening I9. The plate 23 is secured to the outer face of the end sill in any suitable manner, as by welding, as shown at 24.

An abutment wall, in the form of a channel member 25, extends between the center sills. The flanges of the channel member extend forwardly, that is, toward the adjacent end of the car. The member 25 is rigidly connected at each end to the webs of said sills by suitable flange members or brackets 2 6, as shown in Fig. 1. One ange of each angular member or bracket 26 is rigidly secured to the web of the adjacent center sill, as by means of rivets 2l, and the other ange is secured to the Web of the abutment wall 25 as by means of the rivets 28. The abutment wall 25 is provided axially thereof with an angular opening 2 9, which is in axial alinement with the opening I9 in the end sill. A follower block 3I seats against the back or web portion of the abutment wall 25, and is also provided with an openof a hook, which is adapted to engage a couplerr link (not shown) and its opposite end is extended beyond the abutment wall 25 and is screw-threaded, as shown at 35. A suitable draft gear cushioning member 37 is mounted on the inner end,

of the drawbar 22, as will now be described.

This draft gear or cushioning device 31 comprises an open ended follower or gear housing 38, which opens rearwardly and has its end Wall 39 seated against the follower block 3|. For convenience of description the direction toward the hook end of the draft gear will herein be referred to as forwardly and toward the opposite end as being rearwardly. This follower 38 is angular in cross-section, as shown in Fig. 3, and in the form of construction selected to illustrate one embodiment of the invention it is hexagonal and provided on its interior with hexagonal friction surfaces 40. Suitable friction shoes 4|, 42 and 43 are provided for engaging these friction surfaces. Each of these shoes is provided with an outer angul-ar face 44, which is adapted to engage tWo adjacent friction surfaces 4l! of thek chambered follower 38.

Each of the shoes is provided on its inner surface with an inclined wedging face 45 (see Fig. l), which is adapted to be engaged by a corresponding inclined wedging face 46 of a wedge member 4l. The wedge member 41 has three inclined or wedging faces adapted to engage the corresponding inclined faces of the shoes 4l, 42 and 43 for forcing the shoes radially outwardly into frictional engagement with the friction surfaces 46 of the chambered follower 38.

Suitable means are provided for resiliently resisting the free forward movement of the shoes into the chambered follower 38, so that when the wedge member 41 is forced into the follower it will force the friction shoes into said follower and also radially outward into frictional contact with the friction surfaces 4] of the followers. As shown in Fig. 1, a plurality of springs 48, 43, are employed for this purpose. Any desired number of springs may be used, but, as shown, two springs are employed. These springs are telescoped and concentric and seat against the end wall of the follower at their forward ends, and at their rear ends engage a spring seat i, having an axial opening 51 provided on its inner side with an inclined wedging face 52 for each wedge. Each wedge face is adapted to engage a corresponding inclined wedging face 53 on the corresponding wedge member, as shown more clearly in Fig. 1 of the drawings.

A suitable follower is provided for engaging the wedge member 41, and, in the form of construction shown, a follower 54 is employed for this purpose. The follower 54 is provided with an axial internally threaded opening which is adapted to engage the threaded end 36 of the drawbar- The follower is provided with a hub 55, which extends through an axial opening 56 in the wedge 41 for positioning the wedge. This wedge is also provided with an axial kopening 51H, of less diameter than the opening 56, and through which the inner end of the drawbar 22 extends. The follower y54 is also provided with a hub 58,

is employed for this purpose.

extending toward the center of the car, which Lhas alined transverse elongated openings 59 therethrough adapted to be turned to position into alinement with a corresponding transverse opening 53b through the threaded end of the drawbar 22 for adjustably receiving a cotter pin El for preventing relative rotation of the follower and drawbar. The hub 58 may also be castellated at its end, as shown at 59a, for receiving the cotterpin in event the openings or slots 59 are not long enough to compensate for the wear of the parts. The slots 59a permit further adjustment of the follower 54 along the threaded end of the drawbar, if it becomes necessary to take up additional wear on the wedges or on the shoulder 9B of the drawbar hook. The follower 54 has, on the side adjacent the hub 58, radially extending reinforcing ribs Eil integra-1 with the hub 58 and rim 60 on said follower.

The coupler 35 may be in the form of a hook 62, as shown in Fig. 1, and this hook is provided with a keeper 63 the inner ends of which engage in an elongated slot 54, which permits the keeper to be turned above the hook and to drop onto a connecting link when the car is coupled to the next adjacent car, as is usual in such constructions.

Suitable means are provided for biasing or wedging the open end of the housing radially inwardly during the final compressive movement of the gear for counteracting excessive expansive strains on the housing tending to burst the same. In the construction shown.' this is accomplished by providing the inner follower 54 with a depression 6B having an inclined wedging surface 61 extending inwardly from the outer periphery of the follower. This inclined surface is` adapted to engage a corresponding inwardly beveled surface 68 on the open end of the chambered follower 38, so that as the draft gear or cushioning device nears the limit of its compression the inclined surface 61 will engage the inclined surface 68, tending to force the openv end of the follower radially inwardly, thereby preventing a bursting strain on the open end of the follower or housing 38. This is considered an important feature of the invention, because as the draft gear reaches the limits of its compression-as under abnormal loads or under abnormal conditions-enormous radial force tending to burst the follower is developed.

The form of construction shown in Fig. 5 differs from that shown in Fig. 1 in that, instead of using springs for resiliently resisting the movement of the friction shoes Ma, 42a and 43a into the chambered follower 38a, a block of rubber 65 The rubber 65 is preferably, though not necessarily, annular and diamond or lozenge-shaped in cross-section, as shown in Fig. 5. In this form of construction it is not necessary to employ a spring plate corresponding to the spring plate 5I of Fig. 1, so that this plate is omitted, and the rubber block 65 seats directly on the friction shoes Ma, 42E and 43a. Since the remaining portion of the construction is substantially the same as that already described, it is not thought necessary to repeat it.

In this form of construction it will be evident that when the rubber is compressed itwill be forced to ow into the unoccupied portion of the chambered follower, thereby gradually increasing the resistance to the movement of the friction shoes into the chambered follower.

In both forms of construction the resilient members more strongly resist the compression of i the gear as the .compressing -fore increases; and i111 .both ferme 0iY Construction thse .resilient .mffmbelS-:festolfe he p'f/S'OJIQTIHI DQS'OU upon release of Ythe `compressive force.V

It will be noted that in both forms of construction the gear is positioned by -the drawbar, which extends through alined angular openings in the end sill and abutment member. VIt will also be seen that the drawbar is extended'and becomes ,al-part of the draft gear or cushioningdevice.

In operation, any pulling force, whether a steady or a sudden violent force on the coupler hooklZ, will be transferred `directly to the draft gear where any shock -will be partially absorbed by the springs vand by the frictional resistance of the .wedge mechanism. The remainder of the force will, by the reaction of the gear on the abutment 2.5 and associated parts, be expended in drawing the car forward.

`Should the tensile force on the drawbar be sufficient to almost close the gear, or should a sudden and violent pull be .of such intensity as to all but closethe gear, the internal wedging faces fil of the follower 54 will .engage the external inclined wedging faces SE of the follower or housing 3T and cam the latter inwardly, thus preventing excessive .expansion `of the open .end of the latter.

It is thought from the foregoing, taken in connection with the accompanying drawings, that the construction and operation of my device will be apparent to those yskilled in the art, and that changes in size, shape, proportion and detail may be made without `departing from the spirit and scope of the appended claims.

I claim as my invention:

l. In a draft gear, a chambered follower having an interior friction surface, friction shoes .engaging `said surface, a wedge member engaging Said shoes, resilient means for resiliently resisting the inward movement `of said shoes along said surface, a follower engaging said wedge member, and `cooperating means on saidlastnamed follower and the adjacent f end of said chambered follower for resisting the radial expanson of said chambered follower during the final Ycompressive movement of said gear.

2. In a railway car, a pair of center sills, anend sill rigidly connected to said centei` sills, all `of said sills constituting conventional parts of the car frame, an abutment member having rigid connection with said end sill and being vspaced therefrom at substantially the same level therewith, a drawbar having a coupler 'on its forward end extending through alined openings in said front sill and abutment member, Ya friction draft gear surrounding the rear end of said drawbar, and means on said rear end of said drawbar to cooperate with said abutment member for compressing said draft gear in response to forward movement of the drawbar.

3. A drawbar having a coupler member on one end and a friction draft gear on the other 'end of said drawbar, said draft gear comprising an open ended chambered follower and an end follower, wedge mechanism in the open end of said chambered follower for absorbing tensile yshocks applied to said drawbar, and cooperating cam means for forcing the open end of vsaidfollower radially inwardly during the final closing movement of the gear when a pulling force is applied to said drawbar.

4. In a railway car, an end sill, a pair of center sills spaced apart and having their forward ends rigidly connected t0 said end sill at substantially .the same `levelfleis the fend s ill, anabutment mem- :ber at- ;substantially the same level parallel with saidnd sill rand spaced `therefrom-and rigidly connected to said .center sills, said end sill and abutment having alined angular openings therethrough, a drawbar Ahaving ,a coupler member on its `forward .end provided -wi-thfangular portions extending'throug-lii said openings for preventing rotation of `said..drxa.wbar, a friction draft gear on the rear end ,of said .drawbaig means .on said rear end of said drawbar to cooperate with said abutment member' for compressing said draft gear in response-to forward movement of the drawbar, means for compensating for frictional wear on theparts kof said gear, and means for restoring .the parts t0 normal `position upon releaseof said gear.

5. Adraft gear Acomprising a chambered follower having an 'inwardly beveled open end'and having interior friction surfaces, friction shoes engaging said surfaces, a wedge member for forcing said shoes into said follower and radially outward into frictional engagement with said friction surfaces, resilient means 'for yieldingly resisting .theinward movement, of said shoes, a follower engaging theouter .end of said wedge member, and means associated with said gear and lastnamed follower for compressing the gear upon applying a force to said means, said follower having awedging face adapted to engage said beveled face during the final closing movement of said gear for resistingexcessive expansion of the open end of said chambered follower.

6.' A draft gear comprising a chambered follower having an inwardly beveled open end, a cooperating followerhaving an inclined Wedging face adapted to engage said beveled end for forcing the same radially inwardly upon abnormal compressive movement of said gear, friction mechanism `-between said followers and adapted to engage said chambered follower when the gear is compressed, and resilient means/for resisting lthe compression of Vsaid gear and for returning the parts to normal position after release.

7. Adraft gear comprising a pair of followers normally spaced'apart, one of said followers being chambered with the open end turned toward the other follower and having inwardly beveled wedging ifaces, friction shoes 'engaging the inner wallsof said chambered follower, wedge means engaging said shoes andthe other follower, inclined wedgingv faces for engaging said beveled faces for vbiasing the open end of said follower radially vinwardly upon abnormal compression of the gear, and means for restoringthe parts to normal position after release.

8. In afdevice of the` class described, a drawbar having acoupler hook on one end and its opposite end threaded, a follower adjustably mountedon the threaded end 'of said drawbar, a chambered follower having a closed end and an open end adjacent to but spaced from said firstnamed follower, friction mechanism within said chambered follower frictionally engaging` the interior wallof said last-named follower, wedge means engaging-said mechanism, resilient means for restoringthe parts to normal position after release, and cooperating means on said followers for biasing the open end of said second-named follower radially inwardly immediately prior to the closing of sai-d gear under compression.

9. In a draft gear, a pair of followers spaced apart, one of said followers being hollow with an open end turned toward the other follower, wedging and friction mechanism in said hollow '7' follower tending vto expand said open end radially outwardly when the gear is compressed, and means for biasing the open end of said follower radially inwardly during the final compressive movement only of said gear.

10. In a railway car having an end silland a pair of spaced apart center sills rigidly connected to said end sill, an abutment rigidly connected to said center sills and parallel with the adjacent end sill and in spaced relation therefrom at substantially the same level therewith, a drawbar extending through openings in said end sill and abutment member, the outer end of said drawbar having a coupler member integral therewith and having screw threads on its inner end, a follower threaded on the screw threaded end, a chambered follower having an open and a closed end and through which said drawbar extends,` a follower block between said closed end and said abutment, friction shoes having wedge faces engaging the interior of said chambered follower, a spring seat engaging said shoes, resilient means between said spring seat and the closed end of said follower, a wedge member engaging wedging faces on said shoes and engaging the follower threaded on said drawbar, and plates secured to said end andy center sills above and below drawbar. f

11. In a railway car, an end sill, a pair of center sills spaced apartv and having their forward ends rigidly connected to said end sill, an abutment member parallel with said end sill at substantially the 'same levelV therewith, and spaced therefrom and rigidly connected to said center sills, said end sill and abutment having alined angular openings therethrough,` a drawbar having a coupler member on its forward end provided with angular portions' extending through said openings for preventing rotation of said drawbar, a friction draft gear on the rear end of said drawbar, means on said rear end of said drawbar to cooperate with said abutment member for compressing said draft gear in response to forward movement of the drawbar, means for compensating for frictional wear on the parts of said gear, and spring means for restoring the parts to normal position after release.

l2. A drawbar having a coupler member on one end and a friction draft gear on the other end of said drawbar, said draft gear comprising an open ended chambered follower and an end follower, wedge mechanism in the open end of said chambered follower for absorbing tensile 'shocks applied to said drawbar, cooperating cam means for forcing the open end of said follower radially inwardly during the final closing movement only of the gear when a pulling force is applied to said drawbar, and an annular block of rubber loaenge-shaped in cross-section for restoring the parts to normal position when said gear is released after compression.

i3. In a railway car, a pair of center sills, an end sill at 'substantially the same level rigidly connected to said center sills, an abutment member at substantially the same level having rigid connection with said end sill and spaced therefrom, a drawbar having a coupler on its forward end extending through alined openings in said end sill and abutment member, a friction draft gear surrounding the rear end of said drawbar,

theY level of rsaid said draft gear comprising friction and wedging mechanism and a rubber block engaging portions of 'said mechanism for restoring the parts to normal position upon release after compression, and means on said rear end of said drawbar to cooperate with said abutment member for compressing said draft gear in response to forward movement of the drawbar.

14. A draft gear comprising a casing angular in cross-section and having a plurality of interior friction faces, a plurality of friction shoes each engaging two adjacent friction faces, a wedge member having an inclined wedging surface for each shoe for forcing said shoes simultaneously into frictional contact with the corresponding frictional faces of said casing, a movable follower, a drawbar extending axially through said casing and movable follower, means for resiliently resisting the compression of said gear when tension is applied to said drawbar, said means functioning to restore the parts to normal position upon release, means for preventing excessive radial expansion of said casing during excessive tension on said drawbar, and means including said drawbar for limiting the expansion of said gear.

15. In a railway car, a front sill, a pair of center sills spaced apart and having their forward ends rigidly connected tosaid end sill, an abutment member parallel with saidr end sill and spaced therefrom and rigidly connected to said .center sills, said end sill and abutment having alined angular openings therethrough, a drawbar having a coupler member on its forward end provided with angular portions extending through said openings for preventing rotation of said drawbar, a friction draft gear on the rear end of said drawbar, said gear comprising a casing angular in cross-section and having a plurality of friction faces arranged at an angle to one another, a plurality of friction shoes engaging said faces, each shoe engaging two adjacent friction faces, a wedge member having an inclined wedging surface for engaging each shoe, resilient means for resisting the compression of said gear and for returning the parts to normal position after release, a movable follower movable with said drawbar and engaging said wedge member for compressing said gear when tension is applied to said drawbar, and means for resisting radial expansion of said casing during the final compressive movement of said gear.

16. In a draft gear, a hollow member having an inner friction surface, a drawbar extendingr into said hollow member, wedge means movable with said drawbar for radial expansion against said friction surface, yielding means acting on said wedge means to resist longitudinal movement of said drawbar in one direction relative to said hollow member and to progressively increase the radial pressure of said wedge means in response to said longitudinal movement of the drawbar, and means responsive to said longitudinal movement to engage saidv hollow member automatically for reinforcement thereof against radial pressure from the wedge means as the limit of said movement is approached thereby to prevent rupture of the hollow member under peak radial pressure.

JAMES R. CARDWELL. 

